SYDNEY -- Three quick thoughts on Australia 2-1 Syria (Australia through 3-2 on aggregate) in the second leg of the Asian playoff in World Cup qualifying.

1. Brave Syria's dream ended by Australia

Australia edged out Syria in their World Cup qualification clash, winning passage through to an inter-continental showdown with the fourth-placed CONCACAF side --- likely to be Panama or Honduras, with the United States still a possibility.

Syria surprised many when they saw off Uzbekistan and China to claim a place in the fourth round of 2018 World Cup qualification but their fairytale run was brought to an end in the cruellest fashion, with Australia claiming a nervy and scrappy home victory. Tim Cahill was the Socceroos' saviour, his double taking him to 50 for his country.

Coach Ange Postecoglou said afterwards: "Cahill is a great Australian sportsman. He's got an international record that stacks up against the best."

The night was shaping up to be very different in the early stages, though, as Syria took a shock lead through striker Omar Al Soma -- scorer in the first leg draw -- after only five minutes, netting following a swift counterattack. Early nerves had cost the home side dearly, while the Syrian dream was very much on.

Parity was restored moments later thanks to the early release of Australia's right wing-back Mathew Leckie, who swung in an inch-perfect cross, finding the reliable head of the evergreen Tim Cahill to nod home uncontested.

The match became tighter thereafter, with chances in the second half of regular time growing scarce. Extra time was inevitable. The advantage turned Australia's way on 94 minutes when Mahmoud Al Maowas crudely brought down Robbie Kruse on the left touchline, and was shown a second yellow card. With an extra man, Australia were able to find the space and time to pick out Cahill for yet another winner, this time played in by Kruse in the 109th minute.

In an agonising blow for Syria, Al Soma hit the post in the final moments of extra time with Socceroos goalkeeper Mat Ryan soundly beaten.

But thanks to Cahill, Postecoglou's men held on and the Aussie hero said: "For me I'm just glad the boss gave me the opportunity and believed in me to leave me out there.

"It doesn't matter who we play next. We have to take it to the next level now as players."

Tim Cahill scored twice as Australia came from behind to edge past Syria in World Cup qualifying. Ryan Pierse/Getty Images

2. Cahill proves his timeless class

Who else but Cahill could come up with such heroics?

For many years football fans in Australia wondered if any other player aside from the Melbourne City man could actually score for the national team. Those days are long gone, and Cahill is now more of a squad player, but he remains the Socceroos' greatest big-game performer.

His 49th and 50th goals for Australia were arguably two of his most important, given the high stakes and how difficult the home side found the Syrian defence to break down. In the end, it took superb crosses from Leckie and Kruse to allow Cahill to find the back of the net through trademark powerful headers from close range.

No doubt Cahill will go down as one of the Socceroos' best of all-time when the 37-year-old finally retires, but for now his leadership, confidence and goal-scoring is invaluable to a plucky Australian side.

When all team cohesion seems lost -- as it did against Syria -- individual displays like Cahill's are about all they have.

"I'm proud of everything we have done together and how we can help kids watching to follow their dreams," Cahill said afterwards -- a man inspiring those on and off the field.

3. Postecoglou's blushes spared by silly gamble

Socceroos boss Postecoglou took a huge risk by benching his best player in Aaron Mooy for this crucial qualifier. Fortunately for him, the negative impact of this gamble was short lived.

The only logical explanation for Mooy's omission could be the switch to a single holding midfielder in the starting XI, and Mark Milligan was given the nod in this role due to his defensive strengths. However, it was Milligan who turned over possession so cheaply for the home side when Al Soma stole in for the early goal.

An injury to left-back Brad Smith after just five minutes later rather fortuitously saw Mooy enter the fray perhaps earlier than anticipated, but at a goal down Postecoglou surely realised he had no choice but to introduce the Huddersfield midfielder.

It took Mooy some time to get into the rhythm of the game, but once he settled, neat interplay with Kruse, Cahill and James Troisi around the edge of the area showed the difference he can make. Ultimately, Postecoglou's blushes were spared as Mooy played Kruse clean through to cross for Cahill's winner.

Socceroos fans will hope that such a managerial blunder won't cost them in the inter-continental playoff against Panama, Honduras or the United States. If it does, the two games will be Postecoglou's last in charge of the national team.